Chainflex® cables - igus® - #20

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Stranding in bundles tried and tested expensively and efficiently millions of times since 1989 Stranding in bundles eliminates these problems by means of its very sophisticated, multiply stranded internal structure. Here, the litz wires are stranded with a special pitch length first and then the resulting cores are stranded into single core bundles. For large cross sections, this is done around a strain relief element. The next step is the renewed stranding of this core bundle around a tension-proof center – a genuine center cord. (see picture 2) Due to this multiple stranding of the cores, all cores change the inner radius and the outer radius of the bent cable several times at identical spacing distances. Pulling and compressing forces balance one another around the high-tensile center cord that gives the stranded structure its necessary inner stability. Accordingly, the stranding remains stable even under maximum bending stress (see picture 3). What are EMC problems and shield wire breakage? In principle, cable shields must fulfil two tasks:  Protecting the cables from external interferences  Shielding any interferences before transmitting them to the outside Both tasks are equally important because faulty signals can cause considerable consequential damage in the system itself as well as in any external systems. Furthermore, this is an especially problematic point due to the fact that incorrect shielding usually cannot be detected from outside, and this is something that makes the trouble-shooting procedure extremely difficult. How can these kinds of problems arise in the first place? Once again, the answer is to be found in the internal structure of the cable itself: Is the shielding designed for the movements of the cable? Although it may be very easy to shield a fixed cable, it is much more difficult to guarantee the permanent shielding of a moving cable. In the case of so-called "chain-suitable" cables, for example, the stranding bond of an intermediate layer is wrapped up with foils or fleeces. This stranding bond is supposed to guarantee the separation between the cores and the shield braid. But something that functions quite well for the fixed installation of cables is often quite insufficient in the case of moving cables. This has to do with the fact that the foils and fleeces do not create a bond between the stranding, shield and jacket and may fall apart under stress. Consequently, the metallic shield then rubs on the insulation of the cores – short circuits are then to be expected. lasts or your money back! ...the Chainflex® design and why we feel so confident about this design Dictionary of defects Core rupture Failure of electric conductivity due to broken copper wires as a result of subjecting the individual cores to mechanical overload/ tensile load under constant bending stress. In most cases, the causes are incorrect litz wires and/or incorrect stranding pitch directions and lengths. Insulation damage Short circuits due to damage to the insulation above the conductor. The cause can be material fatigue under constant bending stress or material abrasion within the stranded structure. Single-wire breakage of the conductor or the shield braid result in perforation of the insulation. Corkscrew An externally detectable screw-like deformation of the entire cable due to broken copper wires as the result of subjecting the individual cores to mechanical overload/ tensile load during the bending process. In most cases, the causes are unfavorable superstructure properties (stranding in layers, missing center, loose jackets extruded to the form of a "tube") and subjecting the cables to high bending stress. Jacket abrasion The jacket is rubbed off down to the stranding or down to the total shield. In most cases, the causes are incorrect selection of materials and/or unfavorable extrusion processes resulting in detrimental surface properties so that abrasion is an unavoidable effect. Jacket swelling/ jacket breakage Jacket becomes soft and deformed or breaks until the stranding/shield can be seen. The cause can be the incorrect selection of materials with respect to the oils or other chemical substances being used. Shielding losses/ EMC problems Electromagnetic interferences inside or outside an electric cable. In most cases, the cause is shield wire breakage due to mechanical overload with incorrect shield braid angles. Other causes include loose braids over foils without supporting effects or very open coverings.